The present invention relates to a vertical wind generator.
Wind generators or wind power plants are used for example for generating power. Thereby, the wind is harvested. Basically, two different types of wind generators are distinguished, on the one hand the so-called vertical wind generators and on the other hand wind generators having a rotor which rotates about a horizontal axis. The horizontally rotating wind generators usually have a star-shaped rotor, the rotor usually having three blades or wings. The vertical wind generators also have a vertical rotation axis and are inter alia called Darrieus rotors. One embodiment of the vertical wind generators is the so-called Darrieus H-rotor. Vertical wind generators, also called vertical axis wind turbines (VAWT), are usually independent of the wind direction, i.e., a wind tracking system or similar devices are not necessary. Such wind tracking systems consist for example of additional motors in connection with gears, bearings or sensors.
In the prior art, both vertical as well as horizontal wind generators are basically known. Both the horizontal as well as the vertical wind generators have rotors or rotor blades or wings having a constant blade surface. Wind generators having constant blade surfaces are designed for certain wind speeds, i.e., they are most efficient at merely one wind speed or in a certain range of wind speeds. At speeds not lying in and close to the optimal wind speed, i.e. at lower or higher wind speeds, efficiency of such wind generators having a constant blade surface is not ideal.
Vertical wind generators have for example difficulties in particular when starting the wind generator at low wind speeds as the blade surface is too small, i.e. they possibly need an additional starting motor. When using horizontal wind generators, for example at high wind speeds, it is needed to rotate them out of the optimal wind direction, for example also by means of an auxiliary motor, as the rotational speed or the drive of the rotor is getting too high and thus for example an overheating may occur.
DE 44 34 764 A1 describes a Darrieus wind power plant having two aerodynamically-profiled rotor blades arranged so as to rotate symmetrically and aligned parallel to one another and to a rotation axis, wherein on one end of each rotor blade a swivelling starter-flap is arranged. The starter-flaps arranged at one long side of the rotor blades are supposed to be a start-up device for the wind power plant. The starter-flaps are relatively small as regards their surface and thus have a relatively small effect. Said starter-flaps are only active during the start-up of the vertical wind power plant. Furthermore, it seems to be disadvantageous that the starter-flaps negatively influence the aerodynamical properties of the rotor blades, in particular disadvantageous swirls may occur at the edges of the wings or rotor blades.